We have a few IoT devices that connects through VPN to my company's network and then we monitor them using a specific software, there are two escenarios:

1) From a computer inside the LAN we are able to see and connect to the devices, ping them etc, but when we try to monitor variables in real time (The software uses xxxx UDP port) the connection is unstable, quick and lost but sometimes we see some values.

2) Same computer connected from outside through VPN. Successful connection to devices and real time monitoring works perfectly.

Any clue is appreciated, I've been facing this annoying problem from a couple of days ago and is very stressful.